Credit

Caption

Niels and Aage Bohr. Portrait of Niels Bohr (1885- 1962) and his son Aage Bohr (1922-2009), both Danish physicists and Nobel Laureates. Neils Bohr proposed the idea of electron shells and energy levels. He explained the absorption and emission of radiation by atoms as a change in electron energy, further showing that the orbital momentum of electrons was quantized in discrete energy levels. This led to the 1922 Nobel Physics Prize. Aage Bohr put forward the collective model of nuclear structure in 1952. This argued that the distorted shape sometimes seen in nuclei was due to the presence of many nucleons. For this work Aage Bohr shared the 1975 Nobel Physics Prize.